Immunology Flashcards
1
Q
Natural Killer (NK) cells are responsible for killing:
A
Virus infected or Tumor cells
2
Q
Virus-infected or tumor cells need to have _______ to be killed by NK cells
A
Decreased or absent MHC class I protein
3
Q
Do NK cells naturally lyse cells?
A
No. They have perforins and granzymes.
4
Q
Immunoglobulin g (IgG) and Complement C3b are examples of:
A
Opsonins. They work in similar manners to allow phagocytes to phagocyte foreign cells.
5
Q
Where is the site of COMPLEMENT binding in the immunoglobulin molecule shown below?
A
D. In the Fc portion closer to the hinge region
6
Q
Which antibodies can trigger the classical complement pathway?
A
IgG and IgM
7
Q
Major immune mechanisms against Giardia Lamblia (parasites)
A
CD4+ Th cells and secretory IgA production (impairs adherence to bowel mucosa)
8
Q
Children with these diseases have a predisposition for chronic Giardiasis (parasite)
A
IgA Deficiency
X-linked aggamaglobulinemia
Common variable immune deficiency
9
Q
+ Positive selection is responsible for:
And occurs in:
A
Positive selection: only T cells expressing a TCR able to bind self MHC are able to survive.
Thymic cortex.
10
Q
- Negative selection is the process for:
Occurs in:
A
T cells with TCR that binds with very high affinity to cell antigen or MHC class I or II are eliminated (apoptosis)
Negative selecion occurs in thymic medulla
11
Q
Process that eliminates T cells that are overly autoreactive against cell antigens.
May cause autoimmunity if not destroyed.
A
Negative selection. (Eliminates T cells that bind self MHC or self antigens with overly high affinity)
12
Q
___________ prevent the hematogenous spread of candida (prevents disseminated candidiasis)
A
Neutrophils.
*Neutropenic or immunocompromised patients may have candidiasis in blood
13
Q
Patients with HIV (low T-cell count) have increased risk of ___________ candidiasis
A
Superficial.
(oral/esophageal, cutaneous, vulvovaginitis)
14
Q
Programmed Death receptor (PD-1) is expressed on the surface of _________
A
Activated T cells.
15
Q
When PD-1 (on activated T cells) bind to their PD-L1 ligand:
A
Inhibit cytotoxic T cells
(Downregulate immune response, help tumor cells survive)
16
Q
CD28 on T cell binds to _____ on _____ to activate T cell
A
B7 on APC
17
Q
Chronic Granulomatous Disease is caused by a defect in:
A
NADPH oxidase
18
Q
Clinical manifestations of Chronic Granulomatous Disease
A
- Recurrent Catalase + infections (bact+fungi)
- Diffuse granuloma formation
19
Q
NADPH oxidase catalizes the reduction of O2 to ______
This occurs in this structure:_________
A
O2- (superoxide)
Phagolysosomes
20
Q
Absence of green fluorescence on dihydrorhodamine test:
A
Lack of NADPH oxidase = Chronic Granulomatous Disease
21
Q
Nitroblue Tetrazolium (NTB) test detects:
A
NADPH oxidase defect in Chronic Granulomatous Disease.
22
Q
Th1 cyokine that is a key factor in elimination of micobacterium infections
A
IFN - gamma
23
Q
Macrophages infected with mycobacterium produce _____ which in turn, stimulates T cells and NK cells to produce ____
A
IL-12 (macrophages)
IFN-gamma (T cells and NK)
24
Q
Inherited defects involving the IFN-gamma signaling pathway result in
A
Disseminated mycobacterial disease in infancy
25
Clinical presentation of Primary Ciliary Diskinesia
(Kartagener Sx) - AutRes
**- Chronic sinusitis**
**- Bronchiectasis**
**- Dextrocardia / Situs inversus**
- Infertility
26
Failure of **Dynein** arms in cilia to develop normally
**Primary Cilliary Diskinesia** or Kartagener Syndrome
27
Implicated maternal antibodies in **erythroblastosis fetalis** and **hemolytic disease of the newborn**
**IgG** (only Ig that crosses the placenta)
28
If a mother is blood type B and the baby is A, the maternal antibodies formed are:\_\_\_\_\_
Risk of erythroblastosis fetalis? \_\_\_\_\_
Anti-A (IgM)
No risk. IgM does NOT cross the placenta
29
If a mother is blood type O and the baby is B, the maternal antibodies formed are\_\_\_\_
Risk of erythroblastosis fetalis?\_\_\_\_\_
Anti-B and anti-A
Yes. IgG cross the placenta.
30
Can Rh disease occur in the FIRST pregnancy?
No.
31
Can ABO disease occur in the FIRST pregnancy?
Yes
32
Region of the lymph node populated by T lymphocytes and dendritic cells.
Affected in DiGeorge syndrome (22q.11)
Paracortex
33
Antigen present in blood of Rh + individuals
D antigen
34
Risk of transplacental fetomaternal blood exchange increases with\_\_\_\_\_\_\_ and is highest during \_\_\_\_\_\_\_\_
Increasing gestational age
Highest during delivery
35
Anti-Rh(D) immune globulin **(IgG anti-D)** is administered to Rh neg women at _____ weeks and \_\_\_\_\_
**28 weeks gestation** and
**immediate postpartum** period
36
Seronegative spondyloarthropathies (4)
- Ankylosing spondylitis
- Reactive arthritis
- Arthritis associated with IBD
- Psoriatic arthritis
37
Specific Human Leukocyte Type I (HLA I) serotype associated with Ankylosing Spondylitis
HLA-**B27**
38
**Class I HLA** proteins, localization and function
HLA-A, HLA-B, HLA-C
Present in **ALL _nucleated_ cells**
Present **endogenous antigens to CD8+** cytotoxic T cells.
39
HLA Class II proteins, location and function
HLA-DP, HLA-DQ, HLA-DR
Present in **APCs** (macrophages, dendritic cells)
Present **FOREIGN antigens to CD4+** helper cells.
40
Finding
Fusion of sacroiliac joints seen in:
Ankylosing Spondylitis (HLA-B27) MHC Class I
41
Is there a **positive or negative** **_serum rheumatoid factor_** in this 27 year old man with morning stiffness and low back pain?
Sclerosis, ligamentous calcification and vertebral fusion = **Ankylosing Spondylitis** (one of the **seroNEGATIVE spondyloarthropaties**) so **serum Rheumatoid Factor is NEGATIVE**. but HLA-27 +
42
**Hyperacute** rejection occurs in minutes to hours and is secondary to:
**Preformed** antibodies **against graft** in _recipient's_ circulation.
(Fibrinoid necrosis and capillary thrombotic occlusion, mottling and cyanosis)
43
**Acute** rejection occurs in _______ (time)
\< 6 months
44
Exposure to **DONOR antigens** induces **humoral/cellular activation of naive immune cells** in this type of rejection
Acute rejection (\< 6 months)
45
In this type of transplant rejection, there is:
- Vascular wall **thickening** & luminal **narrowing**
- Interstitial **fibrosis** & parenchyma **atrophy**
**Chronic rejection** (months to years, low-grade immune response, refractory to immunosuppresants)
46
Chronic renal allograft rejection presents with:
- Worsening **hypertension**
- Slowly progessive **rise in serum creatinine**
47
Structure of MHC class I protein
Single heavy chain + ß2-microglobulin
48
Presents antigen to CD8+ cytotoxic T-cells
MHC class I
49
Type of antigen presented **to CD8+ T-cells by MHC class I proteins**
**Viruses**
**Tumor** proteins
(Antigens processed in cytoplasm)
50
**MHC class II** proteins present antigen to\_\_\_\_\_\_
**CD4+** helper T-cells
51
Type of antigen presented to **CD4+ helper lymphocytes by MHC class II**
**Bacterial**
52
Antigen presentation in MHC class II (to CD4+) results in:
- Activation of **Th cells**
- Stimulation of **humoral and cell-mediated** immune response
53
Anaphylaxis is a systemic type ____ hypersensibility reaction
1
54
Anaphylaxis is secondary to:
- ________ & _________ degranulation and resultant ________ & ________ release
- **Mast cell** & **basophil** degranulation
**- Hystamine** & **_Tryptase_** release
55
Elevated serum levels of _______ are used to support clinical diagnosis of **Anaphylaxis**
**Tryptase** (released by **mast cells**)
56
The **high-affinity IgE receptor** is found on ________ & _________ and plays a primary role in mediating the **allergic response**
**mast cells** & **basophils**
57
Aggregation of the high-affinity IgE receptor on the mast cell surface leads to:
**Mast cell and basophil degranulation +** release of **hystamine and tryptase** = **allergic response** (Anaphylaxis)
58
When a graft becomes **cyanotic and mottled immediately after** blood vessels connected to those of recipient, there is a ____________ mediated hypersensitivity
**Antibody** mediated hypersensitivity
(**Hyperacute rejection** --\> Preformed ANTIBODIES against graft, already in patient's circulation)
59
Hyperacute rejection is an antibody-mediated reaction (Type ____ hypersensitivity reaction)
Caused by preformed ______ antibodies.
- Type **II** hypersensitivity reaction
- **IgG**
60
Small allergenic substance responsible for immune response in **poison ivy dermatitis:**
\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
Associated with _____ cells
**Uroshiol**
**CD8+** **T-cells** (keratinocyte apoptosis)
61
**Contact dermatitis** is a Type ______ hypersensitivity reaction
Type **IV** hypersensitivity reaction
| (delayed-type)
62
In Type **IV** hypersensitivity reaction, there are 2 phases:
1. ___________ (and duration)
2. ____________ (and duration)
1. **Sensitization** phase (10 - 14 days)
2. **Elicitation** phase (2 - 3 days)
63
In this phase of type **IV** hypersensitivity, hapten-specific T cells are created.
**Phase 1. Sensitization** (Cutaneous dendritic cells - Langerhans - take haptens and express them in MHC-I and II)
64
Exposed skin in a **wood** worker or someone near wood that develops an erythematous **linear** rash with excoriation should make us think in:
**Uroshiol** - induced **type IV hypersensitivity**
(**CD8+ T-cells** - keratynocyte apoptosis)
65
Patient with **T cell function intact** but complete **absence of mature B cells** + severe **deficiency of _ALL_ immunoglobulin** types:
**X-linked agammaglobulinemia** (Bruton)
66
In a patient with intact T-cell function but **lack of mature B-cells** and complete lack of all immunoglobulins, which structure is lacking in their lymph nodes?
Germinal centers (Where B-cells mature)
67
68
If an asymptomatic patient is:
IgM negative for Hep A &
IgG positive for Hep A
but has NOT received vaccine, what is the cause of his laboratories?
He probably had anicteric Hep A when he was a toddler.
69
Hepatitis A virus infection is most commonly silent or subclinical (anicteric) in: ______ \_\_\_\_\_\_\_\_
Young children
| (\< 6 years, 80% asymptomatic)
70
HBsAg first appears ________ (before, after) onset of symptoms, peak when the patient is most ill and becomes undetectable in ________ months
**HBsAg appears _before_** onset of Hep B symptoms
Normally, HBsAg becomes **undetectable in 3-6 months**
71
HBeAg and HBV DNA detected in serum are markers of:
**Active** Hep B virus **replication**
72
If HBsAg continues to be detectable after 6 months, the patient now has:
Chronic Hep B
73
If there is a persistence of HBeAg +
lack of anti-HBeAg, the patient most probably has:
Highly infectious chronic B Hepatitis
74
In Hep B, once the acute disease has resolved, _________ Ig\_\_\_\_ arises.
This antibody confers lifelong immunity.
**Anti-HBsAg** Ig**G**
**\***Remember: if HBsAg persists more than 6 months: it's chronic.
75
If a pediatric patient arrives with dysphagia, breathing difficulty (inspiratory stridor), drooling and a cherry red epiglottis, you think of: __________ that is caused by: \_\_\_\_\_\_\_\_\_\_\_\_\_
**Acute Epiglottitis**
Caused by **Haemophilus influenzae type b** in children
(Hib vaccine REQUIRED, if a child has epiglottitis you think his parents are some piece of shit antivaxxers or the kid is vaccined but has BAD luck!)
76
Surface marker of macrophages
CD-14
| (Macrofourteenphages™)
77
The caseating granulomas in tuberculosis consist on large epithelial _________ with _____ \_\_\_\_\_ granular cytoplasm surrounding a central region of necrotic debris.
**Macrophages**
**Pale pink** cytoplasm
78
Child with
- Severe **bacterial and viral** infections in infancy
- Chronic **diarrhea**
- **Mucocutaneous candidiasis**
Dx?
**Severe Combined Immunodeficiency** (SCID)
## Footnote
**S**evere bacterial and viral infections
**C**andidiasis (mucocutaneous)
**I**mmunocompromised
**D**iarrhea (chronic)
79
**Very low or absent CD3+ T cells**
and
**Very low gamma globulin** levels
Dx?
SCID (Severe Combined Immune Deficiency)
80
Thymic hipoplasia or aplasia seen in:
**- DiGeorge syndrome** (failure in formation of 3rd and 4th branquial pouches)
**- SCID** (Severe Combined Immune Deficiency) b/c of severe T cell deficiency
81
In a child with oculocutaneous albinism, pyogenic infections and progressive neurologic disfunction, you think about: \_\_\_\_\_\_\_\_\_\_\_\_\_\_
That is caused by: \_\_\_\_\_\_\_\_\_\_\_\_\_
**Chediak-Higashi** syndrome
Caused by impairment in **microtubule** function + failure in **phagolysosome** formation
82
In a child with conotruncal cardiac abnormalities, hypocalcemia and craniofacial abnormalities, you think about:
DiGeorge syndrome (22q.11)
83
Triad of:
1. Recurrent infections that **worsen with age** (viral, bacterial and fungal)
2. Easy **bleeding** (thrombocytopenia)
3. **Eczema**
you think about:
**Wiskott-Aldrich** syndrome
(Abnormal functioning of cytoskeleton in cells + no function in B and T cells)
84
Immunodeficiency syndrome caused by insufficient production of mature B cells.
(Predisposition to infection by encapsulated pyogenic bacteria)
**X-linked agammaglobulinemmia** (Bruton)
En **Bruton** estás bien **B**ruto (**no maduras**) y te faltan **celulas B maduras**
85
Form of dendritic cell most commonly found in the skin
Langerhans cell (tennis raquet)
86
This APC expresses both MHC class II and
co-stimulatory B7 surface molecules
Dendritic cells.
87
Plays a role in **granulomatous** inflammation
(B. Langerhans cell)
| (A. Langhans cell)
**Langhans**
(multinucleated giant cell, horseshoe arrangement, multiple nuclei)
88
Which Streptococcus pneumoniae vaccine is recommended in older adults **\>65 years** but NOT in children \< 2 years?
(Polysaccharidae vs. conjugate)
**Polysaccharidae** strep pneumo vaccine for old folks.
Protects against a wider range of serotypes but it is not immunogenic in children younger than 2 years (immature humoral response)
89
This vaccine contains a nontoxic diphteria protein conjugated to polysaccharides, recruits T cells, develops memory B cells and lowers mucosal carriage (herd immunity)
Name and what is it against?
**13-valent pneumococcal _conjugate_** vaccine against Streptococcus pneumoniae
90
Examples of live-attenuated vaccines
**- Rotavirus**
**- Varicella**
**- Measles-Mumps-Rubella (MMR)**
- Adenovirus
- Polio (Sabin)
- Smallpox
- BCG
- Influenza (intranasal)
91
Autosomal Recessive syndrome consisting of:
- Immunodeficiency
- Albinism
- Neurologic defects (nystagmus, peripheral and cranial neuropathies)
**Chediak - Higashi**
(Defect in neutrophil phagosome-lysosome fusion) = abnormal giant lysosomal inclusions
92
What type of hypersensitivity reaction presents **immediately?**
**Type I** (Anaphylaxis and Allergies)
93
Type of hypersensitivity reactions that activate Complement
**Type II** (cytotoxic) and **Type III** (immune complex)
94
Humoral and cellular components of type I hypersensitivity
Basophils & Mast cells
Ig**E**
95
PostStreptococcal Glomerulonephritis (strep pyogenes) is a type _____ hypersensitivity reaction
PSGN is **type III**
(immune complex - deposition of antibody-antigen complexes)
96
Type I hypersensitivity reactions are mediated by the interaction of _______ with preexisting Ig\_\_\_ bound to _______ & \_\_\_\_\_\_\_\_
**Allergen** (antigen)
Ig**E**
**Basophils** & **Mast cells**
(+ cross-linking and degranulation)
97
High-affinity IgE receptor activation occurs by:
**Aggregation** of IgE receptor
98
Deficient communication between T CD4+ activated cells and B lymphocytes with:
- Deficient **CD40L-CD40** interaction
- **Failure of antibody class switching** in B cells
**Hyperimmunoglobuin _M_ syndrome** (Hyper IgM)
99
Child with:
- Recurrent sinopulmonary & gastrointestinal infection
- Infections with **opportunistic** pathogens (*Pneumocystis, Criptosporidium*)
- Failure to thrive
- **LOW** IgG, IgE and IgA
**Hyperimmunoglobulin M syndrome** (HyperIgM)
100
In B cells, during **class switching** to produce different immunoglobulins, which chain stays the same? Which chain undergoes DNA splicing until desired isotype is reached?
- **Variable region** (antigenic specificity of antibody) **stays the same**
- **Heavy chain constant region** undergoes DNA splicing
101
Class switching of immunoglobulins occurs when CD\_\_\_+ T cell is activated and uses its CD\_\_\_\_ ligand to bind to CD\_\_\_\_ on B cell surface.
**CD4+ T cells activated**
Use **CD40L** (ligand)
binds to **CD40** on B cells
102
In HyperIgM syndrome, the most common cause is:
a) Lack of CD40 on B cells
b) Lack of CD40L on T cells
And it is inherited in a __________ pattern
b) **Lack of CD40 _LIGAND_** is most common
HyperIgM is inherited in a **X-linked recessive** pattern
103
Hilar adenopathy, pulmonary infiltrates and non-caseating lung granulomas in an African American female
**Sarcoidosis**!
\*Non-caseating granulomas are sarcoidosis until proven otherwise.
104
Sarcoidosis is a _____ - mediated immune response to an unidentified antigen that results in the formation of \_\_\_\_\_\_\_\_\_\_\_\_
Cell-mediated
granulomas
105
Cell-mediated immunity is driven by:
CD\_\_+ , Th\_\_\_\_ cells that secrete
IL-\_\_\_\_ and \_\_\_-\_\_\_
Cell-mediated immunity:
**CD**_4_**+ Th**_1_****
secrete **IL-_2_** and **_IFN-gamma_**
106
In cell-mediated immunity CD4+ Th1 cells secrete IL-2, which function is to:
Stimulate **AUTOcrine proliferation of _Th1_** cells
107
In cell-mediated immunity, the formation of granulomas is promoted by \_\_\_\_-\_\_\_\_ which is secreted by __________ which in turn, were activated by \_\_\_\_\_\_\_\_\_
Formation of granulomas is promoted by **IFN-gamma** which is secreted by **macrophages** which were activated by **IL-2** (which was secreted by **CD4+ Th1** cells
108
Humoral response is driven by Th\_\_\_\_ CD\_\_+ cells.
**Th**_2_****, **CD**_4_**+** cells drive humoral response.
| (You need two to humor)
109
The products of Th2 CD4+ cells include:
IL-\_\_\_ which promotes IgE antibody production by B cells &
IL-\_\_\_ which promotes the production and activation of eosinophils and B-cell synthesis of IgA
**IL-_4_** = **IgE** ab production in B-cells
**IL-_5_** = **eosinophil** production&activation and **IgA**
110
Deficiency of the complement factors that form the membrane attack complex result in recurrent infections by ___________ species
***Neisseria***
(i.e. bacterial meningitis caused by *N. meningitidis* in a college dorm)
111
Complement factors that form the MAC (Membrane Attack Complex) and fuction
C5b, C6, C7, C8, C9
**(C5b-C9)**
**MAC** forms a **pore in BACTERIAL cell membrane,** leading to electolyte disturbances
112
Binding of **Type I interferons (alpha and beta)** on infected and neighbouring cells results in:
Transcription of antiviral enzymes that **HALT PROTEIN SYNTHESIS**
113
Antiviral enzyme transcription and **halting of protein synthesis** secondary to **IFN alpha and beta** becomes active ONLY in the presence of:
**Double-stranded _RNA_**
(which forms in infected cells that have viral replication) = selective protein synthesis inhibition - only in infected cells.
114
Starting at age 2 months, children should receive which kind of vaccine vs **Haemophilus influenzae serotype b**? Why?
The **Hib polysaccharidae-protein *_CONJUGATE_* vaccine** because it elicits both a **T-cell** dependent immune response as well as an antibody mediated (**B-cell**) immune response.
115
Haemophilus influenzae type B is an encapsulated gram-neg cocobacillus.
Which part of this bacteria is responsible for causing an **antibody-mediated (B-cell) immune response**?
The **polysaccharidae capsule**
**-** primary antigenic constitutent of vaccines for encapsulated bacteria
(Hib, Strep pneumo and N. meningitidis are all encapsulated and antiphagocitic)
116
How does the Hib conjugate vaccine increase immunogenicity ?
With a **carrier protein**
(derived from TT-tetanus toxoid or Outer Membrane Protein OMP from N. meningitidis)
Carrier protein **induces a T-cell dependent stimulation of B-lymphocytes** = production of **memory** B-lymphocytes.
117
Inactivated versions of the influenza vaccine function mainly by neutralizing antibodies against the ___________ antigen
Neutralizing antibodies against the
**Hemagglutinin** antigen
(inhibit binding of hemagglutinin to sialylated receptors on host cell membrane)
118
When a patient is vaccinated vs influenza and later develops natural infection, does the virus infect the host cell?
**No.**
Neutralizing antibodies **inhibit binding of hemagglutinin to sialylated receptors** on host cell membrane and _prevents the live virus from entering cells_ via **endocytosis.**
119
Calcineurin is an essential protein in activation of IL-\_\_\_\_ which promotes the growth and differentiation of \_\_\_\_-cells
**Calcineurin activates IL-2**
**IL-2** promotes growth and differentiation
of **T-cells**
120
Cyclosporine and tacrolimus are immunosupressants used in transplant patients and they act by inhibiting ________ which in turn, activates IL-\_\_\_\_
Cyclosporine and tacrolimus inhibit **CALCINEURIN** activation (which in turn **inhibits IL-2**)
121
Isotype switching (IgM to other Ig) of B-cells occurs in:
**Germinal centers** of lymphoid follicles on lymph node complex.
122
Just remember this, it looks high yield
**APC** - B7 & MHC II ⇒ Antigen
**Th** - TCR & CD28
**Activated Th** - TCR & CD40L ⇒ Antigen
**B-Cell** - MHC II & CD40
**-- IL-4** = IgE // **IL-5** = IgA **--**
123
Heavy chain constant regions are _______ specific
**isotype** specific
(Tipos Heavy) - HEAVY = isoType specific.
124
Light chains are _______ specific and do NOT determine isotype
*light* chain are *antigen* specific
125
Cells that mediate **Delayed-Type Hypersensitivity reactions (DTH)**
(Contact dermatitis, granulomatous inflammation, **tuberculin test**, Candida extract skin reaction)
**T-lymphocytes.**
126
Do Delayed-Type Hypersensitivity reactions (DHT) involve antibody or complement?
No.
127
In DTH (Delayed-Type Hypersensitivity), antigen is taken up by __________ and presented to CD\_\_\_+ lymphocytes on MHC class\_\_\_ molecules.
**dendritic cells** (could be langerhans in skin!)
**CD4+** lymphocytes (helper, usually Th1 lineage)
**MHC class II** molecules. (CD4+ = MHC II)
128
When a tuberculin test is done, antigen is taken by dendritic cells and presented to CD4+ on MHC II, then activated Th1 lymphocytes secrete _______ which recruits ___________ leading to a monocytic infiltration on the site where antigen was introduced.
**IFN - gamma** activates **macrophages.**
129
Predominant cells found on granulomas:
- Epithelioid **MACROPHAGES**
**- Multinucleated GIANT** cells
130
Every time there is a case where there is granuloma formation, you think about this process and cells interacting:
T cells ⇒ T helper kind (**CD4+**)
Think about **MACROPHAGES** and IL-12
Th1 cells = **INF - gamma** (Always in granuloma formation and if there are macrophages involved, think about IFN - gamma)
Activated macrophages = **TNF - alpha** (additional monocytes and macrophages to the area)
131
What type of Th cell drives granuloma formation?
**Th1**
(Granulomas are bad because mycobacterium evade intracellular killing BUT control the infection because they PREVENT bacteria from SPREADING!)
132
The right side of the body above diaphragm is drained by the ____ lymphatic duct into the junction of the right subclavian and internal jugular vein
Right
133
The ______ \_\_\_\_\_\_ drains everything into junction of left subclavian and internal jugular veins
thoracic duct
134
Rupture of thoracic duct can cause:
Chylothorax
135
In splenic disfunction (splenectomy) there is:
\_\_ IgM, ___ complement activation,
\_\_\_\_ C3b opsonization and
\_\_\_\_ suceptibility to **encapsulated** organisms
(\> or \<)
Less IgM \<
Less complement activation \<
Less C3b opsonization \<
More suceptibility to encapsulated organisms \>
136
Vaccines that patients with splenectomy need:
- Pneumococcal (**Streptococcus pneumoniae**)
- **Haemophilus influenzae type b** (Hib)
- Meningococcal (**Neisseria meningitidis**)
137
**Th**ymus is derived from:
**Thi**rd pharyngeal pouch
138
Thymoma (neoplasia of thymus) can be seen in:
Myasthenia gravis
Superior vena cava syndrome
139
HLA subtype associated with myasthenia gravis and graves disease
B8 (BB-8)
140
HLA associated with celiac disease
**DQ2 / DQ8**
| (I ate (8) too (2) much gluten at Dairy Queen)
141
HLA associated with Goodpasture syndrome, multiple sclerosis and hay fever
DR2
2 lungs, 2 kidneys, 2 doctors to treat goodpasture.
142
HLA subtype associated with SLE
**2,3 - SLE!**
| (DR2 and DR3)
143
Rheumatoid arthritis is associated with HLA subtype:
DR4
144
Main cell in charge of **Delayed cell-mediated hypersensitivity** (Type IV) and **acute and chronic organ rejection**
**T cell**
145
T regulatory cells inhibit ___ cell function and express ______ and _______ in their surface
T regs **inhibit Th1**
Express **CD25** and **FoxP3** in their surface
146
Autoimmune Polyendocrine Syndrome - 1 is due to:
**AIRE deficiency** - Omenn syndrome
(Autoimmune Regulator)
Protein is active primarily in the thymus (helping T cells distinguish the body's own proteins from those of foreign invaders)
147
Th1 cell activates macrophages and cytotoxic T cells (CD8+) to kill phagocytosed microbes by secreting:
IFN - gamma
148
Genetic deficiency of FoxP3 in Tregs causes:
**IPEX**
- **I**mmune dysregulation
- **P**olyendocrinopathy
- **E**nteropathy
- **X**-linked
149
Diabetes in male infants + nail distrophy and dermatitis, you think of (Diabeto):
**IPEX** (FoxP3 deficiency on Tregs)
150
Complement binding site and in which region is it located?
**D.**
Located in **Fc region**
(constant, carboxyl terminal, complement binding)
Determines **isotype** (IgG, IgD, etc)
151
Mature, native B cells prior to activation express Ig\_\_ and Ig\_\_ on their surfaces
IgM and IgD
152
MAC (Membrane Attack Complex) defends against gram ______ bacteria
Negative.
153
Classic complement pathway invoves:
IgG or IgM
154
Inhibitors of complement activation on self cells:
DAF (Decay Accelerating Factor) - CD55
and
Cl esterase inhibitor
155
C1 esterase inhibitor deficiency causes:
**Hereditary angioedema**
(unregulated activation of kallikrein) and \> bradykinin
(ACE inhibitors contraindicated)
156
Prevention of formation of anchors for complement inhibitors such as DAF/CD55
Paroxysmal Nocturnal Hemoglobinuria
| (complement-mediated lysis of RBCs)
157
IFN - alpha and beta
- Downregulate ______ \_\_\_\_\_\_\_ on virus infected cells
- Upregulates _______ expression
Downregulate protein synthesis
Upregulates MHC expression
158
EBV receptor on B cell
CD21
159
Type of vaccine contraindicated in pregnancy and immunodeficiency (HIV \< 200 cells)
**- Live attenuated vaccines**
(MMR, Adenovirus, Polio (sabin), Varicella, Smallpox, BCG,
Yellow fever, Influenza (intranasal), Rotavirus)
160
Can toxoid cause disease?
**No.**
It's only a denaatured bacterial toxin (only stimulates immune system but no infective potential)
161
**Serum sickness** is a type ______ hypersensitivity reaction
III because it is an **immune complex** disease.
162
Local subacute immune complex-mediated hypersensitivity reaction (Type III) that consists in:
- Intradermal injection of antigen into a presensitized (IgG) individual that leads to immune complex formation in the skin
(Edema, necrosis and activation of complement)
Arthus reaction
163
Contact dermatitis
Graft vs Host disease
PPD, patch test and candida extract
Are examples of:
Type **IV** hypersensitivity reactions
164
T cell immune function can be tested with
Candida extract.
165
Absent B cells in peripheral blood
Low Ig of all clases
Absent/scanty lymph nodes and tonsils
Live vaccines contraindicated
X-linked agammaglobulinemia (Bruton)
166
Normal IgM and IgG levels
Low IgA
Susceptibility for Giardiasis
Most common primary immunodeficiency
Selective IgA deficiency
167
Low plasma cells,
Low immunoglobulins
Presents AFTER age 2
Risk of autoimmune disease
Common variable immunodeficiency
168
Child with disseminated mycobacterial and fungal infection AFTER administration of BCG vaccine
**IL-12** receptor deficiency (**low IFN - gamma**)
169
Impaired recruitment of neutrophils to site of infection +
* Coarse facies
* Staphylococcal cold abcess (noninflammed)
* Retained primary teeth
* High IgE
* Eczema or dermatologic problems
* Bone fractures from minor trauma
Autosomal dominant **hyper IgE syndrome** (Job)
170
Deficiency of Th17 cells due to STAT3 mutation
AD Hyper IgE syndrome (Job)
171
In a child who has **absent** cutaneous reaction to *Candida* antigens + presents noninvasive *Candida albicans* infections of skin and mucous membranes, they surely have:
**T cell dysfunction**
(Congenital genetic **defects in IL-17** or receptor)
**Chronic mucocutaneous candidiasis.**
172
Bone marrow transplant curative in this type of immunodeficiency
SCID (Severe Combined Immune Deficiency) B+T cells
173
Cerebellar defects + spider angiomas + IgA deficiency
+ Higher risk for lymphoma and leukemia
Ataxia-telangiectasia
(Failure to halt progression of cell cycle + mutations accumulate)
174
Defective CD40L on Th cells (CD4+)
Hyper IgM
175
Falilure to make germinal centers
1. **SCID**
2. **Hyper IgM**
(Note: X-linked agammaglobulinemia NO because they just dont have MATURE B cells but they do show germinal centers - so only low **circulating** B cells.)
176
Leukocytes and platelets unable to reorganize actin cytoskeleton
Wiskott-Aldrich
177
Wiskott-Aldrich
1. **Thrombocytopenia**
2. Eczema
3. Recurrent pyogenic infections
4. **high IgE** and **IgA**
178
Leukocyte adhesion deficiency clinical presentation:
- **ABSENT PUS**
- Delayed (more than 30 days) separation of umbilical cord
- impaired wound healing
- recurrent skin and mucosal BACTERIAL infections
- MORE neutrophils in BLOOD but NOT in infection sites (can´t migrate)
179
Defect in CD18 protein on phagocyte
**Leukocyte adhesion deficiency**
(impaired migration and chemotaxis)
"You can't **adhere** until you're **eighteen**, dear"
180
Progressive neurodegeneration
Lymphohystiocytosis
Partial Albinism
Neuropathy
Recurrent pyogenic infections (Staph+strep)
Mild coagulation defects
Chediak Higashi syndrome
181
Found this in child with Staph aureus infection. Dx?
Probably **Chediak-Higashi**
(**Giant granules** in granulocytes and platelets, pancytopenia)
182
Why are cysteinyl-containing leukotrienes (LTC4, LTD4 and LTE4) important in asthma pathogenesis?
They cause **bronchospasm** and **increase bronchial mucous secretion**
183
Lab technique that uses specific antibodies and a known quantity of radiolalbeled antigen to determine the amount of antigen present in an unknown sample
Radioimmunoessay
184
In there is failure to bind antibody to specific radiolabeled antigen in a radioimmunoassay this indicates that:
When there is no binding after washing the plates, in a radioimmunoassay, it means that the **available antibodies do not share epitopes with the antigen**.
185
If the radiolabeled and unlabeled antigens are identical (have the same epitopes), what happens in a radioinmunnoessay?
They should compete equally for antibody binding sites.
Increasing concentration of of antigen Y decreases measured radioactivity
186
Erythroblastosis fetales or Fetal Disease of the Newborn is most commonly caused by:
Rhesus incompatibility (particularly the D antigen) (rh incompatibility)
187
Findings in Rh+ fetus with Rh- mother
- Release of immature, **nucleated erythrocytes**
- **extramedullary hematopoiesis** (hepatosplenomegaly)
- Anemia (autoimmune hemolysis)
- **Direct Coombs test +**
- Jaundice
- Generalized edema (if hydrops fetalis)
188
Which sensitization can occur during the first pregnancy?
a) ABO
b) Rh
**ABO incompatibility can occur during first pregnancy** but Ig in A and B is IgM (does NOT cross the placenta) so risk for Hemolitic Disease of the Newborn is minimal.
189
What is one of the things that must happen before a fetus gets Hemolytic Disease of the Newborn due to Rh incompatibility?
The Rh- mother must have a previous Rh+ pregnancy
(because maternal immune system needs to have induced anti-Rh (D) IgG antibodies PRIOR to having a subsequent pregnancy)
190
In which disease can we see nonimmune hydrops fetalis?
(negative coombs)
Fetuses with homocygous alpha-thalassemia (Barts) = severe functional anemia with coombs negative test.
191
Which are the main cells implicated in Graft Vs Host Disease? (GVHD)
- Donor **surviving T cells from the graft**
- Recognized **host MHC antigens** as foreign
- **Donor CD4+ and CD8+ _T cells_** = destruction
192
Early signs of Graft Vs Host Disease (GVHD)?
- Diffuse **maculopapular rash** (predilection for **palms+soles** and may desquamate)
- **GI tract involvement** (diarrhea, intestinal bleeding, abominal pain)
- **Liver damage =abnormal liver function tests** (except in liver transplant b/c liver T cells recognize liver as own = do not attack)
193
Child with light skin and silvery hair + recurrent skin and respiratory infections + giant cytoplasmic granules in neutrophils and monocytes + neurologic abnormalities (paresthesias, nystagmus). Dx?
Chediak-Higashi
(AR disorder of neutrophil phagosome-lysosome fusion)
194
Child with the next findings. Dx?
Wiskott - Aldrich syndrome
| (WASP gene)
195
Leukotriene B4 function
Chemotaxis
| (most potent chemotactic eicosanoid)
196
Is thromboxane A2 prothrombotic or antithrombotic?
Prothrombotic.
It induces **vasoconstriction** and **platelet aggregation**.
197
Is prostacyclin prothrombotic or antithrombotic?
Antithrombotic.
Prostacyclin induces **vasodilation** and **lessens platelet aggregation.**
198
Preceding infection in Reactive Arthritis
- **Genitourinary** (Chlamydia trachomatis)
- **Enteritis** (Salmonella, Shigella, Yersinia, Campylobacter, Clostridium difficile)
199
**Reactive Arthritis** findings
(**HLA-B27** b/c it's a seronegative spondyloarthropathy)
- **Assymetric mono or oligoarthritis**
- Enthesitis
- Dactylitis
- **Conjunctivitis**/Anterior uveitis
- **Urethritis** / Cervicitis / Prostatitis
- Oral ulcers + ulcers hands or soles.
- *_Sacroileitis may occur._*
200
When they ask about circulating maternal antibodies (Rh or ABO) always read and pay attention to number of child it is (second child in Rh? CAREFUL!)
This was a PSA.
201
Cough, night sweats, weight loss and an **upper** lobe lesion on chest x-ray is:
**Pulmonary TB**
until proven otherwise.
202
IL-12 function
Induces **activated T helper cells** to **differentiate into Th1 cells.**
203
Finding:
**Multinucleated Langhans cells**
(predominant cells found in **granulomas - TB**)
204
When a case tells you a patient has a Giardia lamblia infection, you immediately know his ______ levels are low or nonexistent.
IgA.
| (most important Ig vs Giardia)
205
If a patient **CANNOT** produce Immunoglobulins, which area of the lymph node is probably atrophic?
**Germinal centers.**
(B cells are in the Germinal centers. If there are no mature B cells, there are no Igs)
206
Child with fever, dysphagia, drooling and a cherry red epiglottis with laryngoscopy probably has:
\_\_\_\_\_\_\_\_\_\_\_\_\_ caused by\_\_\_\_\_\_\_\_\_\_\_\_\_
**Epiglottitis**
caused by **Haemophilus influenza type b** in kids
Almost certainly caused by failed vaccination
207
Toxic Shock Syndrome clinical presentation:
- Fever, vomiting, diarrhea
- **Erythroderma** (diffuse macular rash = sunburn)
- Severe **hypotension or multisystem failure**
- **Elevated Transaminases, elevated CREATININE**
- Desquamation palms and soles
208
Ethiology Toxic Shock Syndrome
- **Staphylococcus aureus** producing:
**Toxic Shock Syndrome Toxin** (TSST)
**SUPERANTIGEN that activates large number of T helper cells.**
209
Interleucins that cause capillary leakage, circulatory collapse, hypotension, shock, fever, skin findings and multiorgan failure in TSS secondary to TSST.
**IL - 2** from T cells
**IL - 1** and **TNF** from macrophages.
210
Immunosupressive agent that inhibits lymphocyte proliferation by blocking IL-2 signal transduction
**Sirolimus**
(blocks mTOR that is necessary for IL-2 signal transduction)
211
Proliferation signal inhibitor that targets mTOR (and thus, inhibits cell growth and proliferation)
Pathway that it inhibits
**Sirolimus binds to FKBP and inhibits mTOR**
Interrupts **IL-2 signal transduction.**
212
Immunoinhibitory drug that selectively targets lymphocytes, reducing B and T cell proliferation and antibody production while promoting T cell apoptosis
Mycophenolate (inhibits de novo purine nucleotide synthesis - IMD inosine monophosphate dehydrogenase)
213
Chimeric antibody directed against CD20 antigen
| (specific to B lymphocytes)
Rituximab
214
NK (Natural Killer Cells) are responsible for killing cells that:
have **decreased of absent MHC class I protein** on their surface.
215
You encounter a cell that expresses **CD16** or **CD56** on its surface.
What type of cell is it?
With what can you activate it?
**NK cell**
Activated with **IFN - gamma** and **IL-12**
216
AR deficiencies of the **IFN - gamma receptor** result in:
**disseminated mycobacterial disease** in early infancy or childhood (can happen with BCG vaccine stain)
217
Defect in CD18 can predispose to:
**Leukocyte adhesion deficiency**
| (delayed separation if umbilical cord, NO PUS, poor wound healing)
218
Hep B serological marker that is detectable during **acute infection** and its **persistence more than 6 months = chronic infection**
HBsAg
219
Hep B serological marker that indicates active viral replication and infectivity. (Detectable during acute infection)
a) HBsAg
b) HBeAg
c) Anti-HBc IgM
d) Anti-HBs
e) Anti-HBe
f) Anti-HBc IgG
b) **HBeAg**
**"e"** de **e**s infeccioso
220
First serological sign of Hep B infection
**Anti-HBc IgM**
(IgM de Mediato. Si HBc core es lo que te infecta de Hep B, entonces si ya tienen IgM contra HBc significa que tu cuerpo ya lo notó como infección "intruso")
221
Serological marker of Hep B that confers long-term immunity
Seen with:
- Cleared infection
- Vaccination
**Anti-HBs**
(Tiene a fuerza que ser anti algo. Cuando es "anti" el cuerpo ya reconoció al antígeno y trabajó para que ya no vuelva a infectar. Si HBs es lo que se ve en acute infection, Anti-HBs es lo que te va a proteger de desarrollar una acute infection)
222
When the serologic of Hep B indicates presence of Anti-HBe, what does it mean?
Indicates less viral replication and infectivity, probably the person will be cured soon.
223
If you find a patient with **Anti-HBc IgG,**
how would you think he acquired it?
In acute or chronic infection
Because Anti-HBc IgG is NOT present after vaccination.
224
The presence of anti-HBc and anti-HBs antibodies in serum without detectable viral antigens indicates:
Recovery from acute hep B infection
225
Patients with chronic hep B have elevated __________ levels ______ months after initial infection.
Chronic Hep B = **elevated HBsAg \>6 months** after initial infection.
226
Chronic Hep B with high infectivity presents with these levels:
**Persistent elevation** of:
- HB**s**Ag
- HB**e**Ag
- HBV DNA
**NO ANTI-HBeAg** (indicates less viral replication and infectivity. They don't have this)
227
A patient vaccinated vs. Hep B has
a) Anti HBs antibodies
b) Anti HBeAg antibodies
c) Anti HBc antibodies
They have **a) Anti HBs antibodies with NO Anti HBc nor Anti HBe**
(because virus never directly infected them. They just got HBsAg from the vaccine and formed Anti HBsAg antibodies.
228
Dendritic cells, macrophages and B-lymphocytes have in common that they present a _______ molecule
**MHC class II** molecule
Dendritic cells, macrophages and B-lymphocytes are all APCs
229
MHC class II molecules are synthesized in \_\_\_\_\_\_\_\_\_\_
MHC class II molecules are synthetized in the **Rough Endoplasmic Reticulum** of APCs
230
```
After MHC class II molecules aggregate in the acidified phagolysosomes and degrade the invariant chain, they load antigen.
MHC class II loads antigen and becomes a molecule-protein complex, they are displayed in the surface of APCs and are available to bind the _______ on __________ and initiate ___ cell response
```
**MHC class II** molecules bind the **TCR** on T-lymphocytes and initiate **T cell** response.
231
Failure to acidify lysosomes leads to deficient expression of MHC __________ bound to foreign antigen and subsequent lack of interaction between ______ and ___ cells.
**MHC class II**
Lack of interaction between **APCs** and **T cells.**
232
Sensitized Th2 cells in the airways promote isotype switching in B lymphocytes to IgE.
What substance do they produce to accomplish this switching?
Th2 --\> IL - 4 ---\> **IgE**
233
Sensitized Th2 cells also produce _____ which recruits eosinophils.
**IL - 5**
234
Main difference between Th1 and Th2
CD4+ cells
Which one is for cell-mediated adaptive immunity + delayed-type hypersensitivity (IV)?
Which one for allergic response in type I hypersensitivity?
**Th1** is for cell-mediated adaptive immunity (**IC pathogens**) and **Type IV** hypersens reactions (delayed)
**Th2** contribute in **type I hypersensitivity** (allergic reactions + anaphylaxis)
235
Which other IL apart from IL-4 do Th2 cells need to produce to promote B-cell immunoglobulin class switching to IgE ??
**Th2** cells produce both:
**IL-4 and IL-13**
for class switch to IgE and mast cell priming
236
Relate the columns:
* *Th1** =
* *IL-1:** fever and inflammation
* *IL-3:** growth+differentiation bone marrow stem cells
* *IFN-gamma:** Activates macrophages, stimulates CD8+ cells, inhibits Th2
* *Th2** =
* *IL-3**
* *IL-5** = stimulates eosinophils
* *IL-4 and IL-13** = promotes class switching IgE
237
Findings in chronic lung transplant rejection:
MONTHS or YEARS after transplantation.
- Progressive scarring of **small** airways (**Bronchiolitis obliterans**)
- Obstructive lung disease (**\< FEV**)
- **Dyspnea** and **dry cough**
238
If histology of a recent lung transplant receptor shows fibrinoid necrosis with hemorrhage and ischemia or "white graft" reaction, you typically think in __________ rejection
**Hyperacute**
239
Most common microorganisms that can infect a person with Chronic Granulomatous Disease (NADPH oxidase deficiency)
Catalase ***POSITIVE +*** organisms destroy their own hydrogen peroxide (H2O2)
**- Staphylococcus aureus**
**- Burkholderia cepacia**
**- Serratia marcescens**
**- Nocardia**
**- Aspergillus**
240
In tight adhesion and crawling, neutrophils become firmly attached to the endothelium by binding with ________ to ___________ on endothelial cells
**CD 18** beta 2 integrins (Mac-1 and LFA-1)
to **Intracellular Adhesion Mollecule (ICAM-1)**
241
Protein at the peripheral intercellular junction on endothelial cells that permits **transmigration**
**PECAM-1**
platelet endothelial cell adhesion molecule 1
242
\_\_\_\_\_\_\_\_ binds to Cyclophilin or FKBP to inhibit \_\_\_\_\_\_
**Cyclosporine or Tacrolimus**
bind to FKBP or cyclophilin
To **inhibit Calcineurin**
243
Bcl - x and Bcl - 2 are ________ proteins
**anti-apoptotic.**
When there is a high level of Bcl-2, cells don't die and errors accumulate.
244
Caspases are \_\_\_\_\_\_\_\_\_\_\_\_\_
proteolytic enzymes
**c**ysteine-**asp**artic-acid-prote**ases**
245
Apoptosis can occur through either the intrinsic (mitochondia-mediated) pathway
or the extrinsic (receptor-initiated) pathway.
Both pathways converge in the activation of \_\_\_\_\_\_\_\_
Caspases.
246
Clinical features of selective IgA deficiency
- **Recurrent sinopulmonary** (pneumonia), **gastrointestinal infections** (Giardia)
- Concommitant **autoimmune disease** (Celiac disease)
- **Anaphylaxis during blood transfusions**
247
When transfusing blood products (RBCs, platelets, fresh frozen plasma), IgA deficient patients may present:
**Anaphylaxis.**
IgA deficient patients should receive blood products that are washed of residual plasma
or from an IgA deficient-donor.
248
Inactivated versions of the influenza vaccine (injection) function mainly by inducing ________ antibodies against the ___________ antigen
**Neutralizing** antibodies
against the **Hemagluttinin** antigen.
249
For signs of inflammation to present in the injection of candida extract on the skin, we need these two cells:
**CD4+ T** cells and **macrophages.**
(These cells recruit **CD8+** so in a way, they are also involved)
250
Which of the following vaccines produces stronger immune responses by acting as a persistent stimulus to activate helper and cytotoxic T cells as well as by creating better IgA mucosal immunity?
a) Live-attenuated oral vaccine (Sabin)
b) Inactivated poliovirus (Salk) vaccine
**Live attenuated oral vaccine (Sabin)**
(intestinal exposure to novel antigens = mesenteric lymph nodes and peyer's patches become activated and synthetize IgA = better mucosal immunity)
251
After X-linked SCID, the second most common cause is:
**Adenosine deaminase deficiency** SCID
252
In X-linked agammaglobulinemia flow cytometry, the main markers that would be low are:
- CD4
- CD8
- CD15
- CD16
- CD19
**CD19**
Because Bruton agammaglobulinemia is failure of B cells to mature (and pre-B cells are CD19 and CD20 +) and panhypogammaglobulinemia (all Ig low)
253
In this autoimmune disease, CD\_\_\_\_ cells induce B cells to synthesize _________ \_\_\_\_\_\_\_\_ and
\_\_\_\_\_\_\_ __________ protein antibodies
**CD4+ T cells**
induce B cells to synthesize:
**Rheumatoid Factor** & **Anti-Citrullinated protein antibodies** (ACPAs)
254
Rheumatoid factor is an antibody (IgM) specific for the _____ component or Ig\_\_\_
**Fc component of IgG**
255
People with CREST syndrome present _________ antibodies
CREST syndrome = **Anticentromere antibodies**
256
People with SLE present this type of antibodies:
- **Anti-dsDNA** antibodies
257
The Monospot test assesses \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
And it is positive in ________ \_\_\_\_\_\_\_\_\_\_ from ________ \_\_\_\_\_ Virus
serum's ability to a**gglutinate sheep erythrocytes**
**Positive in _infectious mononucleosis_** from
**Epstein Barr Virus**
258
The _____ receptor is expressed on T-lymphocytes and plays an important role in DEATH and apoptosis. (Activation-induced cell death)
Fas
259
People with SLE may have mutations involving ____ of _____ ligand resulting in **excessive accumulation of autoreactive T cells** and **defect in activation-induced T lymphocyte death.**
**Fas** or **Fas ligand**
260
Individuals with **IL-12 receptor deficiency** suffer from severe mycobacterial infections (Th0 --\>X --\>Th1 )
Administration of _________ is indicated in this patients to activate macrophages.
**IFN - gamma**
261
Th ------\> Functions of IL-2
- Stimulate **growth of CD4+ and CD8**+ cells and **B cells**
- Activates **NK** cells
- Activates **Monocytes**
